Kauri gum, also known as New Zealand amber, is a natural material that has been extracted from the resin of the kauri tree. This resin was often used in the 19th century as a varnish for furniture and boats, and as a component in the production of high-quality linoleum. There are few exact synonyms for the term "kauri gum," but some close variations include "amber," "resin," and "gum." Other terms may also be used interchangeably depending on the context, including "tree sap," "balsam," and "pitch." While these terms don't precisely match the unique properties of kauri gum, they evoke a similar natural material that can be used in similar ways.